@techreport{Manson2023,
author = {Manson, S. and Schroeder, J. and Van Riper, D. and Knowles, K. and Kugler, T. and Roberts, F. and Ruggles, S.},
title= {National Historical Geographic Information System: Version 18.0},
year = {2023},
doi = {10.18128/D050.V18.0},
publisher = {IPUMS},
address = {Minneapolis},
}